1. Field of Invention
The present invention relates to an electronic timepiece with a power generator function.
2. Description of Related Art
Replacing the battery is not necessary with timepieces that have a power generator function, and such timepieces have therefore come into widespread use.
Electronic timepieces with a power generator function store the power produced by the power generator in a secondary battery for use. Japanese Examined Patent Pub. JP-A-S61-61077 teaches a timepiece that has a function for indicating the remaining operating time to the timepiece user, and detecting and displaying how much voltage is left in the secondary battery in order to initiate recharging as may be required.
While the prior art can thus detect the voltage and remaining capacity of the secondary battery, the user is unable to confirm whether the power generator is currently producing sufficient power.
This means that if the timepiece has a manual power generator that produces electricity as a result of the user turning the crown of the timepiece, for example, the secondary battery may not be sufficiently charged because the user does not know whether if sufficient power has been produced. More specifically, when the crown of the timepiece is wound to drive the rotor of the power generator so that the magnetic flux crossing the coil as a result of rotor rotation changes, power cannot be sufficiently generated unless the rotor turns at a sufficiently high speed. This means that the secondary battery may not be sufficiently charged no matter how long the crown is turned if the user winds the crown slowly.
An electronic timepiece with a power generating means according to the present invention enables the user to easily determine the power generation state of the generator.